Waist-to-Hip Ratio Calculator

Choose male or female and enter your waist and hip measurements. The tool divides waist by hip, shows the ratio to two decimals, and says whether it is at or above or below the WHO threshold for your sex:

• Men: 0.90
• Women: 0.85

These are the WHO thresholds as they are widely reported: a ratio at or above them is linked with a substantially increased risk of metabolic complications. It gives one cut-off for each sex rather than a set of low, moderate and high bands, so the tool doesn't grade results further. The ratio is a screening figure from two tape measurements: an estimate, not a diagnosis.

Because the thresholds differ, the same ratio can fall on either side of the line:

The defaults are the third row: 85 cm waist and 95 cm hip, a ratio of 0.89. Make sure the right sex is selected, since it changes the comparison, not the ratio.

The comparison uses the full ratio, while the display rounds it. A man with an 89 cm waist and a 99 cm hip has a ratio of 0.8990. The tool displays 0.9 and still reports it as below the 0.90 threshold, which is correct: 0.899 is under 0.90. A woman with an 81 cm waist and 95 cm hip is in the opposite situation: 0.8526 displays as 0.85 and counts as at or above.

If your result sits right on the line, re-measure both sites. A difference of half a centimetre at the waist can be enough to cross it.

The boxes are labelled centimetres, but a ratio has no units. A 34 inch waist and 38 inch hip give the same 0.89 as the equivalent centimetre figures. What you can't do is mix them, one in inches and one in centimetres. Measure both at the same sitting, with the tape level and snug but not pulling in the skin.